reporter: but then bill clinton's former white house doctor, a retired navy rear admiral weighed in on cnn. >> i'm a republican. so i like chris christie a lot. i want him to run. i just want him to lose weight. i'm a physician more than i'm a democrat or republican and i worry about this man dying in office. >> reporter: to the governor and his familythat was no joke. so he called the doctor today to sound off. >> that a doctor in arizona who has never met me, never examined me, never reviewed my medical history or records, knows nothing about my family history, could make a diagnosis from 2,400 miles away is completely irresponsible. my children saw that last night. and she sat there on tv and said i'm afraid he's going to die in office. my 12-year-old son comes up to me last night and says, "dad, are you going to die?" >> reporter: like christie, millions of americans, more than one-third of adults in the u.s., struggle with their weight. just look at the popularity of nbc's "biggest loser" and the first lady's "let's move" campaign. >> keep it up! >> reporter: tonight, dr. mariano repl